patch 9.0.0805: filetype autocmd may cause freed memory access

Problem:    Filetype autocmd may cause freed memory access.
Solution:   Set the quickfix-busy flag while filling the buffer.
diff --git a/src/version.c b/src/version.c
index b4756ca..7f72a2c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    805,
+/**/
     804,
 /**/
     803,